Re: [PATCH] vfio-pci/zdev: require KVM to be built-in

[Pierre Morel]

On 8/16/22 08:04, Randy Dunlap wrote:
> Hi--
>
> On 8/15/22 02:43, Pierre Morel wrote:
> > Thank you Randy for this good catch.
> > However forcing KVM to be include statically in the kernel when using VFIO_PCI extensions is not a good solution for us I think.
> >
> > I suggest we better do something like:
> >
> > ----
> >
> > diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> > index 6287a843e8bc..1733339cc4eb 100644
> > --- a/arch/s390/include/asm/kvm_host.h
> > +++ b/arch/s390/include/asm/kvm_host.h
> > @@ -1038,7 +1038,7 @@ static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
> >   #define __KVM_HAVE_ARCH_VM_FREE
> >   void kvm_arch_free_vm(struct kvm *kvm);
> >
> > -#ifdef CONFIG_VFIO_PCI_ZDEV_KVM
> > +#if defined(CONFIG_VFIO_PCI_ZDEV_KVM) || defined(CONFIG_VFIO_PCI_ZDEV_KVM_MODULE)
>
> This all looks good except for the line above.
> It should be:
>
> #if IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)
>
> Thanks.

Yes, better, thanks.
How do we do? Should I repost it with reported-by you or do you want to 
post it?

Pierre


> >   int kvm_s390_pci_register_kvm(struct zpci_dev *zdev, struct kvm *kvm);
> >   void kvm_s390_pci_unregister_kvm(struct zpci_dev *zdev);
> >   #else
> > diff --git a/drivers/vfio/pci/Kconfig b/drivers/vfio/pci/Kconfig
> > index f9d0c908e738..bbc375b028ef 100644
> > --- a/drivers/vfio/pci/Kconfig
> > +++ b/drivers/vfio/pci/Kconfig
> > @@ -45,9 +45,9 @@ config VFIO_PCI_IGD
> >   endif
> >
> >   config VFIO_PCI_ZDEV_KVM
> > -       bool "VFIO PCI extensions for s390x KVM passthrough"
> > +       def_tristate y
> > +       prompt "VFIO PCI extensions for s390x KVM passthrough"
> >          depends on S390 && KVM
> > -       default y
> >          help
> >            Support s390x-specific extensions to enable support for enhancements
> >            to KVM passthrough capabilities, such as interpretive execution of
> >
> > ----
> >
> > What do you think? It seems to me it solves the problem, what do you think?
> >
> > Regards,
> > Pierre

--
Pierre Morel
IBM Lab Boeblingen